<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<button class="abc" onclick="alert(1); return false">1</button>
	<a class="abc" href="javascript:alert(1);">2</a>
</body>
<script src="lib/jquery/jquery-2.1.1.min.js"></script>
<script>

	$('.abc').click(function(ev){
		alert(2);
		return false;
	})
//	$('.abc').off();
//	$('.abc').on();
	$('.abc').click(function(ev){
		alert(3);
		return false;
	})


</script>
</html>